1. Technical Field
The present invention relates to a display device, and more particularly to a display device that can precisely control a light source by measuring the quantity of light from the light source under uniform conditions.
2. Discussion of Related Art
A liquid crystal display (LCD), which is one of the most widely used types of flat panel displays (FPDs), includes two substrates, on which electrodes are formed, and a liquid crystal layer interposed between the two substrates. In such a liquid crystal display, an image is displayed when liquid crystal molecules of the liquid crystal layer are rearranged in accordance with voltages being applied to the electrodes, and thus the quantity of light passing through the liquid crystal layer is adjusted.
In order to improve the display quality, a display device, which adjusts the luminance of light provided from a light source in accordance with an image being displayed on a display panel, has been developed. Such a display device can adjust the luminance of the light source by measuring the luminance of light provided from the light source and feeding back the measured luminance value.
The display device may include an optical sensor measuring the luminance of light, and in order to accurately measure the luminance of the light source, the optical sensor should measure the light under uniform conditions. However, if external conditions of the display device are changed, the measurement conditions of the optical sensor are also changed, and an error may occur in the measured value. For example, if the display device is thermally deformed due to a change of an external temperature, a change may occur in a relative position between a constituent element, such as, for example, a light receiving hole, and the optical sensor. The change in the relative position between the constituent element, such as the light receiving hole, and the optical sensor causes a difference in the quantity of light incident to the optical sensor, and thus a measurement error may occur.
Accordingly, there is a need for a structure capable of measuring the light under uniform conditions even if the external conditions are changed.